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NELSON W.' BURNETT, Y0F SOUTH HADLEY, MASSACHUSETTS.

Letters .Pate-nt No. 74,297, dated February 11, 1868.

IMPROVEMENT IN lPAT'IlEItliT-SQUARE.

ftlgr .themle reftmt tn in time @time @tout tut milling mit tf tige same.

ToA ALL WHoMfIT MAY coNoERN: t

Be it known that I, NELSON W. BURNETT', of South Hadley, Hampshire county, Commonwealth of Massachusetts, have invented a new and useful Improved Pattern-Square; and I do hereby declare that the following is a fnlland exaothdescription thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon. i y i v In the drawings the gure shows a perspective view of my improved square. i

'.lhis invention consists of a device for marking out mortises, &c., upontimber preparatory to cutting theV same out, being principally adapted to the uses of carpenters and joiners.

In construction it is formed of two-rightwangled pieces, A and--B, which are connected together by crossbars a, b, c, and d, arranged at right angles to them. Both the right-'angledbpieces A and B, und the connecting ones, a, b, 8m., are lslotted longitudinally, sothat any measurements permitted by the size of the instrument may be made in the form of a parallelogram. The piece A has, however, two slots inreachl face, therones, eand e', being forl guides upon the ends of the cross-pieces a, b, c, 8vo., to work in,- and thus-keep these pieces at a right angle to the piece A. The pieces of this'device are all markedin the scale roost useful to the work it is designed for, and small set-screws, 1, 2, 3, '4,V 5, 6, '&e., are arranged so asf'toclamp the pieces firmly together at any measurement desired. "One of the cross-pieces, say b,.may `beata` nextended so as to form a' measuring-rule .if desired. y

The operation of this device is asfoliows': In order to' obtainl the measurement of amortise, the rightangled pieces A and B are moved, so as to be the propei` distance apart, to indicate the two oppositesides of the parailelogram, and the'cross-pieces on that face of the instrument moved so as. to mark the other sides of the figure, the lines being drawn on the inside edges of the pieces forming therfoufr sides ofthe figure, the scale on these edges also indicating'themeasures; Thus `the pieces A: and B, upon the upper face, F, ofthe instrument,` l

form, at their` edges o and o', two opposite and parallel sides of the figure to he marked out, while the crosspieces a, and b, at their'edges, p and p', form the other sides,..the scale marked upon these edgesshowing the measure of these sides. l, I 4 i i Many other operations, such as tenoning, crossfeutting, ne., may be facilitated by this Vtool, and it is pecniiarly useful in house-building and ship-building, where the same measures are used n great many times over. Now, having described my invention, what I claim as new, and desire to secure by Letters Patent,- is' The pieces A and B,i`orming 4right angles, in lcombination with the pieces a, b, c, Vand d, placed at. right angles withA and B, and adjustable relatively with each other in slots, in such manner that mortises or tenons maybe marked at .one adjustment of the tool upon two sides of a right-angled timber, substantially as described'.

NELSON w. rBUaNE'rT.

Witnesses:

R. F.. HYDE, E. H. HYDE. 

